Method and apparatus for the treatment of sheet material

ABSTRACT

A method for the continuous treatment of fabrics in which the fabric passes between two moving bands to one or both is applied a bleaching or other chemical preparations the bands with the fabric sandwiched therebetween traversing a heated treatment chamber or kier with means for controlling the temperature of the treatment zone and the concentration of the chemical preparations, the fabric after treatment being rinsed and wound into a roll. Apparatus is also provided for carrying out the method.

United States Patent Inventor Francis Elric Stringer Marple, England App]. No. 773,201 Filed Nov. 4. 1968 Patented July 27, 1971 Assignee Leemetals Limited Maccleslield, England Priority Nov. 11, 1967 Great Britain 51397/67 METHOD AND APPARATUS FOR THE TREATMENT OF SHEET MATERIAL 5 Claims, 1 Drawing Fig.

US. Cl 68/5, 68/ 14,68/204, 118/257 Int. Cl B054: 1/14, B056 3/136, B05c 3/138 Field of Search ..68/204 5.4, 5.5,44; 1 18/257 [56] References Cited UNITED STATES PATENTS 887,755 5/l908 Benjamin 68/204 3,046.77] 7/1962 Bailey 4. 68/44 X 3,056.275 10/1962 Williams 68/44 X FOREIGN PATENTS 1,314,555 12/1962 France 68/204 Primary ExaminerWilliam 1. Price Attorney-Norris and Bateman ABSTRACT: bands to A method for the continuous treatment of fabrics in which the fabric passes between two moving bands to one or both is applied a bleaching or other chemical preparations the bands with the fabric sandwiched therebetween traversing a heated treatment chamber or kier with means for controlling the temperature of the treatment zone and the concentration of the chemical preparations, the fabric after treatment being rinsed and wound into a roll. Apparatus is also provided for carrying out the method.

SHEET MATERIAL This invention relates to an improved method and apparatus for the treatment of sheet material and particularly to the treatment of textile fabrics.

In the treatment of textile fabrics and particularly in carrying out bleaching processes where the fabric is passed through a bath several disadvantages have been encountered; the liquid in the bath may be contaminated by impurities from the fabric; fumes may be given off to contaminate the surrounding atmosphere and when the bath contains sodium chlorite corrosion of the walls of the bath becomes a serious problem.

The object of the present invention is to provide a method and apparatus for the treatment of sheet material in which the above mentioned and many other disadvantages of known methods are removed or at least substantially overcome.

According to the invention the method of treating fabric comprises the steps of passing the fabric in sheet form between adjacent faces of a pair of moving bands, applying a liquid to at least one face of one of the bands, retaining the fabric in contact with the bands for a predetermined time and finally removing the fabric from between the bands when the treatment is completed.

The method may be carried out in a machine comprising a pair of endless bands, each mounted on a series of carrying rolls whereby over a predetermined distance of travel the bands are located in close face to face proximity with each other; means for rotating the bands and a treatment chamber through which the fabric passes between the bands.

The invention will be described with reference to the accompanying drawing showing a diagrammatic longitudinal section ofa machine for carrying out the method as applied to the bleaching of textile materials.

Two endless carrier bands 10, 11 pass over a plurality of guide rollers l2, 13 arranged around and within a closed container or kier 14 having an inlet slot 15 in the top and an outlet slot 16 in the base. At the outlet end of the chamber 14 is a washing bath 17 forming a seal and containing water or other rinsing liquid and having a pair of squeeze rollers 18 and 19 mounted thereon, the roller 19 being in the form ofa batching roller. At the inlet end of the chamber 14 there is provided a feed roller 20 for the material, a pair of expander rollers 21 and a delivery chute and drip tray 22. A device 23 for applying hear and/or liquid to the fabric 32 passing over the chute 22 (shown in dotted lines) may be provided. Two nip rollers 24 and 25 are provided adjacent the delivery end of the chute.

Two applicator pads 26 are arranged adjacent two of the rolls 12 above the chamber for applying liquor to the bands 10, 11. The applicator pads 26 are connected to a liquor reservoir 28, the latter including means (not shown) for varying the amounts and concentrations of liquor independently fed to the pads 26.

Perforated steam pipes 30 are provided in the chamber 14 extending vertically and horizontally thereof to supply steam to the chamber M during the passage of the fabric therethrough for treatment.

The endless bands 10, 11 are traversed over the rollers l2, l3 and the fabric 32 in continuing sheet form passes from a beam or plait to the feed rollers 20, through the expander rollers 21 and onto the band 12 as it passes over a roller 12 the width of the band being greater than that of the fabric. The band 12 and fabric pass onto the chute 22 where the fabric may be wetted out or heated. On leaving the chute 22 the fabric 32 together with the band 10 is fed between the nip of the rollers 24 and 25 and is thus located between the bands 10 and 11. The fabric between the bands 10, 11 is fed into the chamber 14!, through the inlet slot 15. Thus the moving length of fabric is confined between coextensive carrier band portions as it moves through a predetermined path length,

The operative faces of the bands 10 and 11, that is the faces which are in contact with the fabric 32, are coated prior to engaging the opposite sides of the fabric 32 respectively with a stabilized bleaching agent, such as a mixture of sodium chlorite and sodium bicarbonate and a suitable acid such as formic acid.

The bands 10 and 1111 and cloth 32 pass over the rollers 13 within the chamber 14 in a sinusoidal path so that steam from the pipes 30 acts upon the bands to heat the fabric therebetween as it passes through the treatment zone.

Upon leaving the chamber 14, through the outlet slot 16, the fabric and bands pass into the washing bath and water seal 17 where the bands 10 and l l are separated from the fabric 12 and from each other and are fed back through squeegees 23 to the inlet region of the chamber 14 for continuous operation. Meanwhile, the cloth 32 is passed out of the washing bath l7 and through the nip of the squeeze rollers 13 and 19 which remove excess moisture. The washing jets 31 serve to assist in the final removal of any bleaching reactant from the bands 10 and Ill and the fabric 32.

It will be appreciated that while the bands and fabric are passing through the chamber M, the bleaching reagents diffuse through the fabric and thus react in the normal manner to bleach the latter. The fabric is passed through the treatment zone at a speed dependent upon the characteristics of the fabric and the bleaching reagents employed.

The temperature of the steam from the pipes 30 may be controlled to maintain a temperature for the treatment chamber in the region of 100 C. The concentration of the bleaching reagents can be adjusted accordingly and reset at any time during the continuous process. The resetting may be effected almost instantaneously to vary the degree of bleach from batch to batch, the forward end of one batch being attached to the trailing end of the fabric of the previous batch.

The bands 10 and ll may be constructed of a plastics or textile material, the preferred material being polypropylene or Neoprene coated cloth or Titanium sheet and may be provided with drip catches 27.

If required, the edges of the bands overlapping the cloth may be sealed prior to entering the chamber 14 by applying along the edges of one or both bands an adhesive coating or strip such as silicone adhesive so that as the bands come together their edges are sealed completely to enclose the fabric during treatment thereof. Alternatively, the edges may be held closely together by closely associated parallel moving strips or stationary bosses or rails past which the bands travel to be held in close relationship.

Processes other than bleaching may be carried out by the method such as dyeing, desizing, or merely heat treatment. In the treatment zone, the heat can be applied either from heating elements or by live steam or any other form of heat exchange.

The treatment zone in the chamber 14 may be operated under pressure desired by providing a seal along the inlet and outlet slots through which the fabric passes.

lf required, the fabric may be treated with a chemical or other form of treatment prior to passing between the bands. Furthermore, one chemical can be applied to the bands to react with that applied to the fabric prior to passing between the bands. in this way up to three different forms of chemical treatment can be separately applied to the fabric prior to entering the treatment zone in the chamber 14.

Some of the advantages of the process of the invention are now referred to l. Firstly the apparatus used is self-threading and continuous in operation and thus its speed of operation is increased. In addition there is substantially no tension applied to the fabric during its passage through the machine, therefore the process can be used for the treatment of delicate fabrics, for example, knitted or netted fabrics. It has been found that for bleaching, at least, the process is much reduced in time by virtue of the fact that reagents are enclosed between the bands and can therefore retained between the bands whilst passing through the treatment zone, a period of approximately seconds. A further advantage lies in the fact that the adjustability of the supply of reagents allows the concentration or nature ofvthe latter to be altered at will during the process without the need of changing the contents ofa liquid bath as in conventional methods.

The invention is thus particularly applicable for bleaching, when employing sodium chlorite which is highly corrosive when acidified, to many machinery parts, since the chlorite on one band and the acid on the other band are kept out of contact with the parts of the machine which could be affected. The reaction takes place between the bands, which are made ofa resistant material immune to the reacting liquids.

I claim:

1. A fabric treatment machine comprising a pair of endless bands, means for applying chemical agents to the adjacent faces of each band, a series of carrying rolls over which the bands pass whereby over a predetermined distance of travel the bands are located in close face to face proximity with each other, a heated treatment chamber through which the fabric passes between the bands, a rinsing bath containing liquid through which the fabric passes on emerging from the treatment chamber, said bath forming a seal for said chamber, and squeeze rollers through which the fabric passes after rinsing to remove surplus moisture.

2. The machine defined in claim 12, wherein one of said squeeze rollers is a batching roller on which the treated fabric is wound.

3. The apparatus defined in claim 1, wherein said bands are wider than the fabric carried therebetween.

4. The apparatus defined in claim 3, wherein said bands are sealed along opposite edges to enclose the fabric during passage between said bands.

5. The apparatus defined in claim 1, wherein said bands are composed of a plastic or like sheet material inert with respect to the treatment liquid. 

2. The machine defined in claim 12, wherein one of said squeeze rollers is a batching roller on which the treated fabric is wound.
 3. The apparatus defined in claim 1, wherein said bands are wider than the fabric carried therebetween.
 4. The apparatus defined in claim 3, wherein said bands are sealed along opposite edges to enclose the fabric during passage between said bands.
 5. The apparatus defined in claim 1, wherein said bands are composed of a plastic or like sheet material inert with respect to the treatment liquid. 